With the scan callback now being callable from
any context, these unlocks/locks can go away.
This makes the code easier to understand, since
callers of these functions must no longer be
aware that the mutex may be dropped.

As Stanislaw is working on iwlwifi scanning, I
didn't change it to take advantage of the new
mac80211 semantics.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We were always using the max transmit power when scanning.  Now we use the
values passed to the driver by the mac80211 stack, so that we comply with
regulations.
Signed-off-by: NLuciano Coelho <luciano.coelho@nokia.com>
Reviewed-by: NSaravanan Dhanabal <ext-saravanan.dhanabal@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch is a complete rewrite of the scanning code.  It now includes a
state machine to scan all four possible sets of channels independently:
2.4GHz active, 2.4GHz passive, 5GHz active and 5GHz passive.  The wl1271
firmware doesn't allow these sets to be mixed, so up to several scan commands
have to be issued.  This patch also allows scanning more than 24 channels per
set, by breaking the sets into smaller parts if needed (the firmware can scan
a maximum of 24 channels at a time).

Previously, the scanning code was erroneously scanning all channels possible
actively, not complying with the CRDA values.  This is also fixed with this
patch.
Signed-off-by: NLuciano Coelho <luciano.coelho@nokia.com>
Reviewed-by: NSaravanan Dhanabal <ext-saravanan.dhanabal@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The scanning code is going to get a bit more complex, with proper support for
active/passive scans together with 2.4GHz and 5GHz.  In the future, also a
new type of scan (periodic scan) will be added.  When all this is
implemented, the code is going to be much more complex, so we'd better
separate it into a separate file.

This patch doesn't have any impact on functionality.
Signed-off-by: NLuciano Coelho <luciano.coelho@nokia.com>
Reviewed-by: NSaravanan Dhanabal <ext-saravanan.dhanabal@nokia.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>